Semiconductor light emitting devices such as ultraviolet, blue, and green Light Emitting Diodes (LED), or blue-violet and blue Laser Diodes (LDs) have been developed, using nitride semiconductor such as gallium nitride.
In order to enhance efficiency and intensity of semiconductor light emitting devices, it is desired to enhance internal quantum efficiency and light extraction efficiency. It is essential to improve crystal quality of the semiconductor layer in order to enhance internal quantum efficiency. For enhancement of light extraction efficiency, there is a configuration in which a substrate having irregularity is used. There is still room for enhancement to have high crystal quality and high light extraction efficiency at the same time.